With fewer U.S. forces in Afghanistan, Marines in a desolate patch of Helmand province find themselves vulnerable to Taliban attack. They seek help from locals, who distrust them and the militants.

A helicopter casts a shadow on a road at Camp Leatherneck, a U.S. military… (Adek Berry, AFP/Getty Images )

HELMAND PROVINCE, Afghanistan — The sun pounds down on the U.S. Marine sergeant and the tribal elder in this faceless, bone-colored plain.

"We haven't seen any Taliban," the silk-bearded Afghan says, with a grin too large. The sergeant, broiling in his bulletproof vest, anticipates crackling gunfire at any minute. He knows the man is lying and he expects him to lie.

This barren, anonymous-feeling landscape matters because it sits outside the biggest U.S. military and coalition base in Helmand province, known as Camp Leatherneck, a miniature city built in the middle of nowhere. The camp has served as the restive province's command center for American forces during their two-year troop buildup aimed at disrupting the Islamist militants.

FOR THE RECORD: An earlier version of this article referred to the U.S. military base Camp Leatherneck as Camp Bastion. The militant attack in September occurred at Camp Bastion, a conjoined allied base.

Now, with those additional troops having departed, American forces cannot leave Camp Leatherneck without getting fired at or bombed on any given day. An unprecedented assault on an adjoining base in mid-September saw 15 Taliban fighters enter, blow up six Harrier jets and three refueling stations and kill two Marines before they were stopped.

The daily fight right beyond the wire is bitter and unwelcome evidence of the stalemate that exists in southern and eastern Afghanistan. U.S. officers commend their forces for fighting bravely and they praise the growing strength of their Afghan counterparts, who they say will be able to take on the Taliban when the last of the U.S.-led coalition forces leave Afghanistan in 2014.

"We are still a province at war, there is no doubt about that. We have been for a while and it will continue to be, but it is a province where things have improved a lot over the course of three, four years," said Marine Maj. Gen. Mark Gurganus, the commanding U.S. officer in Helmand. "I am watching these young [Afghan] guys step up and take the fight."

But today, the Americans confront an enemy still capable of absorbing punishing hits and then turning around to attack when it suits them, including the assassination of Afghan politicians and security officials. If the Americans hope another year of training will result in Afghan security forces strong enough to push the Taliban back, the militants appear to believe today belongs to them, and tomorrow, without the Americans, does so even more.

It is in this atmosphere that the Marines patrol Boldak, the current name of this no-man's land, home to as many as 20,000 people scattered across dry ravines and gulches about five miles from Camp Leatherneck. As the armored trucks chug down the road, children in white and brown robes spot the Americans and rush after them, trying to strike the convoy with stones, a daily ritual the Marines have become used to. In Iraq, even in the worst of days, children would see a U.S. convoy and chase it in hope of receiving a soccer ball or candy. Here, youngsters use the American vehicles for target practice.

The convoy stops in the middle of Boldak's brown igloo-like huts dotted across the ghostly hills that encircle Camp Leatherneck.

The Marines are relieved to be here and not stuck on the road for hours, lest a 60-pound bomb explode beneath one of their armored vehicles.

As the Marines walk into the narrow alleys between compounds, some of them stand poised with M-16s aimed toward the horizon. They expect sniper fire, or a rocket shot off by a fighter hidden from view, who will then speed away on a motorcycle. At the same time, battle casualties are rare on either side.

The sergeant and an Afghan interpreter wade through a sea of tiny boys, and the elder, with his white robe and cane, approaches. The dry terrain is home to Bedouin hamlets, where people settle during the cooler months to cultivate poppies, then move away in the withering summer heat. The U.S. military has opted to tolerate it rather than infuriate the local population by destroying lucrative crop so close to their base.

The elder shakes the sergeant's hand, seemingly happy to welcome him.

The sergeant breaks the ice by asking, through the interpreter, what the villagers are growing. The interpreter, unrecognizable in sunglasses and armor, afraid of allowing his identity becoming known to the Taliban, stands between them.

The elder says they are cultivating wheat, but the sergeant sees dried-out poppies that look like small garlic bulbs scattered on the ground. He chooses not to mention it.

"Ask him if he wants to help us out at all," the Marine tells the interpreter.

"Sure, why not? I'll help you as much as I can," the elder wheezes. "We know you guys. We can't be friends with the Taliban."

Like all villagers here, the sergeant thinks, the elder's primary concern is to remain safe while waiting to see who wins the war.